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kondaur [170]
2 years ago
14

Why does the pink color, which forms at the point where NaOH comes into contact with the solution (HCl) in the flask, disappear

more slowly near the endpoint?
Chemistry
1 answer:
Novay_Z [31]2 years ago
4 0
Answer is: because pH value of solution is changing.
Balanced chemical reaction: NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l).
pH of sodium hydroxide solution is above seven (basic), when solution of hydrochloric acid is added, pH slowly dropping until it became neutral solution (pH is equal seven) and that is endpoint of titration.
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Calculate the grams of so2 gas present at stp in a 5.9 l container. (r = 0.0821 l·atm/k·mol)
Neko [114]
There is an exact value for the standard volume at standard conditions of 1 atm and 273 K. This standard volume for any ideal gas is 22.4 L/mol. Thus,

Moles SO₂ = 5.9 L * 1 mol/22.4 L = 0.263 mol

The molar mass for SO₂ is 64.066 g/mol. So, the mass is:

Mass = 0.263 mol * 64.066 g/mol = <em>16.87 g SO₂</em>
6 0
2 years ago
Consider the reaction H2(g) + Cl2(g) → 2HCl(g)ΔH = −184.6 kJ / mol If 2.00 moles of H2 react with 2.00 moles of Cl2 to form HCl,
zalisa [80]

Answer:

ΔU=-369.2 kJ/mol.

Explanation:

We start from the equation:

Δ(H)=ΔU+Δ(PV), which is an extension of the well known relation: H=U+PV.

If Δ(PV) were calculated by ideal gas law,

PV=nRT

Δ(PV)=RTΔn.

Where Δn is the change of moles due to the reaction; but, this reaction does not give a moles change (Four moles of HCl produced from 4 moles of reactants), so Δ(PV)=0.

So, for this case, ΔH=ΔU.

The enthalpy of reaction given is for one mole of reactant, so the enthalpy of reaction for the reaction of interest must be multiplied by two:

2 reactant moles*\frac{-184.6kJ}{mol}

ΔU=-369.2 kJ/mol.

4 0
2 years ago
1. If ice is heated at a constant pressure of 0.00512 atm, it will______ . 2. If ice is heated at a constant pressure of 1 atm,
evablogger [386]

Answer:

sublime, melt, condense, deposit

Explanation:

1. When ice is warmed at a steady pressure 0.00512 atm, it will be sublime.  

2. It will be melt when ice is warmed at a consistent pressure of 1 atm.

3. If water vapour pressure is continued to increase at a temperature of 100  C, it will be condense.  

4. If water vapour pressure is continued to increase at a temperature of -50 C, it will be deposited.

5 0
1 year ago
What is the mass of solute in 200.0 L of a 1.556-M solution of KBr
sergejj [24]
The molarity of KBr solution is 1.556 M
molarity is defined as the number of moles of solute in volume of 1 L solution.
the number of KBr moles in 1 L - 1.556 mol
Therefore in 200.0 L - 1.556 mol/L x 200.0 L = 311.2 mol
Molar mass of KBr - 119 g/mol 
mass of Kbr - 311.2 mol x 119 g/mol = 37 033 g
mass of solute therefore is 37.033 kg
4 0
1 year ago
A vessel contains Ar(g) at a high pressure. Which of the following statements best helps to explain why the measured pressure is
Luda [366]

Answer:

4. The combined volume of the Ar atoms is too large to be negligible compared with the total volume of the container.

Explanation:

Deviations from ideality are due to intermolecular forces and to the nonzero volume of the molecules themselves. At infinite volume, the volume of the molecules themselves is negligible compared with the infinite volume the gas occupies.

However, the volume occupied by the gas molecules must be taken into account. Each <u>molecule does occupy a finite, although small, intrinsic volume.</u>

The non-zero volume of the molecules implies that instead of moving in a given volume V they are limited to doing so in a smaller volume. Thus, the molecules will be closer to each other and repulsive forces will dominate, resulting in greater pressure than the one calculated with the ideal gas law, that means, without considering the volume occupied by the molecules.

5 0
2 years ago
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